“In general, some of that information, as it just refers to UVB rays, for example, is accurate. But there is a lot of other information on the label that’s not particularly accurate because the sunscreen protection factors – the SPF value – those only help against UVA. So you have to actually make sure that a product protects against both.”

Hansen and other sunscreen critics aren’t just worried about the products’ effectiveness. U.S. Senator Charles Schumer of New York recently urged the federal Food and Drug Administration to study potential links between a common sunscreen ingredient – retinyl palmitate – and cancer.